Mptms self-assembled monolayer deposition for ultra-thin gold films for plasmonics

Abstract

(3-mercaptopropyl)trimethoxysilane (MPTMS) as an adhesive layer helps realize plasmon compatible few monolayer uniform gold films. We present, significantly faster, thermally assisted evaporation and immersion methods for MPTMS monolayer deposition. Presence and properties of MPTMS monolayers are established by fourier transform infrared spectra, ellipsometry and atomic force microscopy. Sub-nanometer rough, 0.7 nm thick MPTMS monolayers are used to fabricate large area gold gratings by electron beam lithography followed by either lift-off or reactive ion etching. In addition to retaining the plasmonic response over broadband, MPTMS layer helps realize 5 nm thin gold films of uniform coverage.